EP2788618B1 - Rear casing, rotor blade with rear casing, and a wind turbine that comprises such a rotor blade - Google Patents

Description

The present invention relates to a rear box for a rotor blade, in particular a wind turbine, with a pressure-side surface, a suction-side surface, a rear edge separating the pressure-side and suction-side surfaces, and a connection side opposite the rear edge, which is adapted for attachment to a corresponding connection surface of the rotor blade is.

The invention further relates to a rotor blade for a wind turbine, with a supporting part, a rotor blade root encompassed by the supporting part for attachment to a rotor, a wind turbine, a pressure-side blade surface, a suction-side blade surface, and a trailing edge separating the pressure and the suction-side surface . In addition, the invention relates to a wind turbine.

Due to the increased efforts in the field of electricity generation from renewable energy sources, wind energy plants are being used increasingly more.

New ways are constantly being sought to make the known wind turbines more powerful and efficient.

For example, wind turbines are known which, in departure from traditional rotor blade shapes, use rotor blades with conformable blade surfaces. The maximum profile width of the rotor blade, i.e. the length of the chord between the rear edge and the foremost point of the rotor blade nose, does not assume its maximum value in cross section in a central region of the rotor blade but very close to the end region of the rotor blade on the side of the rotor hub. Contrary to many years of prejudice in the industry, this has resulted in a significant increase in efficiency. A wind turbine with such a rotor blade is, for example, out EP 1 514 023 B1 known.

This widening of the area of the rotor blade on the hub side is ensured by attaching a rear box to the rotor blade, which in turn also has a rear edge which is aligned with the rear edge of the rotor blade when the rear box is attached to the rotor blade.

In particular in the case of larger wind turbines with tower heights of above 80 m, the problem arises according to the prior art that the rotor blades with a corresponding rear box have such a large profile width that they can only be transported with great effort.

So far, this problem has been countered by transporting the rear box separately to the rotor blade to the installation site and attaching it there to the rotor blade. This creates additional logistical and time expenditure.

US 2011/0142668 A1 discloses a rotor blade for a wind power plant, which is composed of an upper and a lower shell element, which are connected to one another using edge structure elements or connecting caps at the front and rear edges.

GB 2 062 120 A discloses a structural unit of a fluidic device, which in the flow direction is composed of several structural elements arranged one behind the other, which are connected to one another.

DE 20 2011 103 091 U1 or WO 2011/088835 A2 disclose rotor blades which are equipped in the hub-side or root-blade-side section of the rotor blade with an airfoil section or extension section. Wing section or extension section each have a plurality of individual segments arranged next to one another in the longitudinal direction of the rotor blade, which are fastened to the rotor blade in accordance with the curved shape of the flow surface to be generated.

WO 2008/0052677 A1 discloses a rotor blade with a twistable central support spar, which is enclosed by a plurality of mutually movably connected front edge and rear edge linings and thus has a shape which can be adapted to changing wind conditions.

US 4,618,313 A discloses a wing of an axial propeller with a straight chord, which is equipped at its rear edge with a one-piece flap which is oriented at an angle to the chord of the wing.

The present invention was therefore based on the object of specifying a rear box, a rotor blade and a wind energy installation in which the disadvantages mentioned above are mitigated as far as possible.

The invention achieves the object on which it is based in a rear box of the type mentioned at the outset by dividing the rear box into a foot segment having the connecting side and one or more head segments having the rear edge and which can be coupled to the foot segment. The invention makes use of the knowledge that a substantial saving of time and quality improvement can be achieved in that all those work or manufacturing steps which are associated with great effort, for example because they require high manufacturing precision, should not be carried out at the installation site if possible , rather already in the factory. One step that requires a high degree of manufacturing or assembly precision is to connect the connection side of the rear box to the connection surface of the rotor blade. This is primarily due to the curvature or curve shape of the pressure and suction-side surface edges on the connection side of the rear box. The rear box designed according to the invention allows the foot segment to be attached ex works due to its subdivision into a foot segment and one or more head segments. Due to the connectable design of the foot segment and the head segment (s), subsequent attachment of the head segment (s) to the foot segment is possible either ex works or at the installation site. The coupling, which is already created during the manufacture of the rear box, saves a significant amount of time and money when retrofitting the head segment (s) to the installation location, while at the same time, by attaching the foot segment to the rotor blade beforehand, a further increase in efficiency is optionally possible.

The invention is advantageously further developed in that the foot segment has a separate subdivision level for each head segment, in which the head segment or segments can be coupled to the foot segment. The provision of separate subdivision levels for each head segment simplifies the assignment to an area of the foot segment which has the respective subdivision level.

According to an alternative advantageous embodiment, the foot segment has a continuous subdivision level for several or all head segments, in which the respective head segments can be coupled to the foot segment. A continuous subdivision level, which extends over several or all of the assignment areas between the foot segment and the head segments, offers the advantage that a number of segments can be coupled in succession on the common subdivision level with the foot segment and thereby support one another. As a result, the effort to fix the position of the several head segments is significantly reduced.

According to a further preferred embodiment of the invention, the one or more subdivision levels are arranged such that the maximum profile width of the rotor blade is 4 m or less when the foot segment is connected to the rotor blade. The fact that a longitudinal division is selected which leads to a maximum profile width in the above-mentioned range means that the transportability of the The rotor blade and the base section of the rear case attached in advance have been significantly improved.

The subdivision planes are preferably aligned essentially in the longitudinal direction of the rotor blade axis. An angle in a range of 30 ° or less is preferably spanned between the rotor blade axis and the subdivision plane or planes.

According to the invention, the foot segment and the head segment (s) can be positively coupled to one another.

In a particularly preferred embodiment of the rear case, the form-fitting coupling between the foot segment and the head segment or head segments takes place by means of a hinge-like connection.

According to the invention, the foot segment for positive locking has a plurality of mutually spaced projections with a first recess, and the head segment or the head segments each have a multiplicity of spaced projections with a second recess, the projections of the foot segment and the projections of the head or segments can be aligned with one another. Aligned here is understood as referring to the center points of the mutually facing ends of the first and second recesses and the distances are preferably selected such that a projection of the foot segment can engage in the distance between two adjacent projections of the head segment or segments and vice versa. A projection of the head segment or segments can accordingly engage in the distance between two adjacent projections of the foot segment.

The advantage of such a hinge-like coupling of the foot segment to the head segment or segments can be seen in particular in the fact that the alignment of the parts with respect to one another is very simple, and for connecting a multiplicity of projections, which are aligned one behind the other, with recesses by means of a single connecting member, which according to Art a hinge pin can be formed, is made possible.

The rear case according to the embodiment described above is advantageously further developed by an elongated body, the cross section of which is adapted to the cross section of the first and second recesses, and which can be inserted into the plurality of first and second recesses if these are essentially aligned with one another. The diameter of the first recesses is preferably substantially the same as the diameter of the second recesses. The diameter of the elongated body is particularly preferably adapted to the diameter of the first and second recesses in such a way that it is accommodated in the first and second recesses without play or as largely as possible without play. The more precise the fit between the elongated body and the recesses, the less movement there is between the head segment or segments and the foot segment, which has a positive effect on the overall stability of the rotor blade.

In a further preferred embodiment of the rear box, the elongated body is designed such that in the assembled state it extends through the multiplicity of the projections of the foot segment and of the head segment or head segments. This creates a connection that is similar to that of a rod hinge or piano hinge.

The elongated body preferably consists of a fiber composite material, in particular of glass fiber reinforced plastic. The advantage of a suitably designed elongated body is to be seen in the fact that the elongated body has a certain elasticity, which makes it possible to deform the elongated body along a curved path and also to pass through such projections which are not strictly coaxial with respect to their recesses are, but are arranged along a curved path.

The rear case according to the invention is preferably designed in such a way that the projections of the foot segment and of the head segment or segments are arranged along a curved path. The curvature of this path particularly preferably corresponds to the contour of the rotor blade. In combination with an elastic, elongated body, this means that the positive connection can be arranged directly on the outer edge of the adjacent segments, that is to say the foot segment and the head segment or segments, for example directly on the wall thereof. The curvature curve resulting from the curvature of the wall is the contour curve of the rotor blade and at the same time ensures that a swiveling movement between the Foot segment and the head or head segments, which is normally allowed with a hinge, is prevented due to the curvature. This further increases the stability of the rotor blade.

According to a further preferred embodiment, the wall of the first and second recesses is partially or completely lined with a plastic. Polyethylene is preferably provided as the plastic. The lining of the wall of the first and second recesses is particularly preferably designed as a hollow cylinder which is enclosed on the outside by a layer which is firmer than the material of the hollow cylinder, for example by a layer made of glass fiber reinforced plastic. This improves the absorption of the pressure forces by the projections.

According to a further preferred embodiment of the rear box according to the invention, the projections are designed as tabs and preferably have a scrim made of two or more layers of fiber composite material. Depending on the dimensioning of the rotor blade and the size of the wind force to be expected, the projections must withstand different tensile and compressive loads. The dimensions of the rotor blade and the rear box can be taken into account by appropriate thickness of the scrims.

Furthermore, the projections preferably have a foam body enclosed by the scrim. According to a first preferred alternative, the foam wedge is made of an elastic foam. This has the advantage that any compressive forces acting on the projections designed as tabs can be damped. According to a second alternative, the foam wedge is made of a non-elastic, in particular hardened, foam. This has the advantage that the rigidity of the projections designed as tabs is further increased.

Particularly preferably, the base segment has one or more rails for positive coupling, and the head segment or the head segments have one or more corresponding rails, the rails being able to be brought into engagement with one another, preferably by means of sliding. It has been found that the use of a rail system, which provides for a positive connection by pushing it on, represents a particularly good compromise between positioning accuracy and manageability, which makes this type of positive connection Coupling between the foot segment and the head segment at the installation site of a wind energy plant favors.

In an advantageous development, a respective rail on the foot segment or the rail of the associated head segment corresponding to it has a dovetail profile. Such form-locking connections with dovetail profiles and correspondingly designed recesses with a rear grip ensure high positioning accuracy. Optionally, the arrangement of a single rail with a corresponding part for the head and foot segment is possible, or the parallel arrangement of several rails is possible.

According to a particularly preferred alternative, the rail or the rails of the foot segment and the corresponding rail or rails of the head segment (s) are of identical design. These preferably have an essentially L-shaped cross section. This makes it possible to arrange identical rail elements produced with a single tool both on the side of the foot segment and correspondingly on the side of the head segment or segments which can be brought into engagement with one another. When using such identically designed rail elements, it is particularly preferred to assign two rails to the foot segment for each head segment, and to assign two corresponding rails to the respective head segment. The rails are preferably aligned parallel to one another.

According to a further preferred embodiment of the invention, at least two, preferably three or four head segments are assigned to the foot segment.

According to a preferred embodiment, one or more head segments with a respective length of 3 m or less are assigned to the foot segment. For the preferred embodiment with several head segments, the following advantage results, explained using the example with three head segments per foot segment: with the same length (in the longitudinal direction) of the head segments, the largest cross-section in the longitudinal direction and the smallest cross-section in the longitudinal direction are stackable. In this way, it is possible to load these two head segments nested one inside the other on one side of a closed 40 'container, and to load the remaining middle head segment on the other side of the container. Thus, preferably three of the groups of as arranged above are Head segments can be arranged one behind the other in the 40 'container. As a result, all of the head segments required for a wind turbine with three rotor blades can advantageously be transported in a compact arrangement. This advantage arises analogously for other longitudinal divisions and other assignments of head segment per foot segment.

Preferably, two parallel rails are assigned to the foot segment for each head segment, and each head segment has two corresponding, parallel rails for engagement with the rails of the foot segment.

The rear box is preferably further developed in that the pressure-side surface and the suction-side surface are each delimited by an edge on the connection side, the respective edge profile of which is adapted to the contour of the connection surface of a rotor blade. As a result, the rear box hugs the rotor blade optimally and seamlessly.

In a preferred development of the invention, one or more areas for applying adhesives, preferably adhesive such as a high-strength epoxy resin compound, are prepared in the interior of the rear box. This enables the rear box to be glued to the connecting surface of the rotor blade. Optionally or alternatively, the areas of the edges on the connection side of the rear box are prepared for applying the adhesive. By gluing the rear box to the rotor blade, a significant cost saving is achieved compared to screwing or riveting with conventional rotor blades. The cost saving results in particular from the fact that on the one hand the considerable material costs for screws, nuts, rivets etc. can be saved and on the other hand the introduction of reinforcing elements only has to be reduced if at all. With conventional connection types, a large number of holes had to be provided, each of which meant a structural weakening, which had to be compensated for by means of reinforcements, additional struts, etc. This can now be omitted.

Gluing the rear box to the rotor blade is only made possible with satisfactory accuracy by the divisibility according to the present invention, because it is no longer necessary to assemble the entire rear box at the installation site. In addition, there is no need to transport the equipment required to produce a precise and sufficiently durable adhesive connection,

The foot segment and / or the head segment or segments preferably each have a web in the region of the subdivision, which extends from the pressure-side surface to the suction-side surface, the rail or rails being arranged on the webs. The webs thus serve on the one hand to close off the inner surfaces of the foot segment and the head segments, either completely closed or partially opened, and also have a stabilizing function. The rails can be preassembled on the webs, so that at the installation site, all that is actually required is to simply slide the coupling or coupling of the head segment (s) onto the foot segment.

According to a further preferred embodiment, the rear box has locking means which are provided in a coupled state for selectively locking or releasing the relative position between the foot element and the at least one head segment. The locking means are preferably designed as a bolt connection, particularly preferably as a shear bolt connection. In those embodiments of the invention which have a plurality of head segments, only the head segment closest to the rotor blade root is preferably locked. Because the head segments are preferably supported against one another, the locked head segment closest to the rotor blade root also serves to lock the other head segments.

The invention achieves the object on which it is based in a rotor blade of the type mentioned at the outset by attaching a base segment of a rear box to the rotor blade according to one of the preferred embodiments described above.

The invention also achieves the object on which it is based by a rotor blade of the aforementioned type, in which the foot segment is coupled to one or more head segments in such a way that a rear case is formed on the rotor blade according to one of the preferred embodiments described above.

The invention also achieves the object on which it is based in a wind power installation having a tower, a nacelle, a rotor and at least one rotor blade connected to the rotor, in that the rotor blade is designed in accordance with one of the preferred embodiments of the invention described above.

Figur 1

eine Windenergieanlage gemäß der vorliegenden Erfindung,

Figur 2

einen Abschnitt eines Rotorblatts gemäß der vorliegenden Erfindung gemäß einem ersten Ausführungsbeispiel in einem ersten Montagezustand,

Figur 3

den Abschnitt des Rotorblatts aus Figur 2 in einer zweiten Montagestellung,

Figur 4

den Abschnitt des Rotorblatts aus den Figuren 2 und 3 in einer dritten Montagestellung,

Figur 5

einen Abschnitt des Rotorblatts aus den Figuren 2 bis 4 in einer vierten Montagestellung,

Figur 6

einen Hinterkasten für ein Rotorblatt gemäß einem zweiten Ausführungsbeispiel der Erfindung in einer ersten Montagestellung,

Figur 7

den Hinterkasten aus Figur 6 in einer zweiten Montagestellung,

Figur 8

den Hinterkasten in der Montagestellung gemäß Figur 7 in einer anderen Ausrichtung,

Figur 9

ein Fußelement für einen Hinterkasten gemäß dem zweiten Ausführungsbeispiel der vorliegenden Erfindung,

Figur 10

eine Detailansicht eines Fußsegments und eines Kopfsegments des erfindungsgemäßen Hinterkastens in entkoppeltem Zustand,

Figur 11

eine Detailansicht eines Fußsegments und eines Kopfsegments für eine Hinterkasten gemäß der vorliegenden Erfindung in gekoppeltem Zustand,

Figur 12

einen Abschnitt eines Rotorblatts gemäß der vorliegenden Erfindung mit einem Hinterkasten gemäß einem dritten Ausführungsbeispiel der Erfindung,

Figur 13

eine Detailansicht des Hinterkastens gemäß Figur 12, und

Figur 14

eine schematische Darstellung eines Teils des Hinterkastens gemäß den Figuren 12 und 13.

The invention is described in more detail below on the basis of preferred exemplary embodiments and with reference to the attached figures. Show here

Figure 1

a wind turbine according to the present invention,

Figure 2

a section of a rotor blade according to the present invention according to a first embodiment in a first assembly state,

Figure 3

the section of the rotor blade Figure 2 in a second assembly position,

Figure 4

the section of the rotor blade from the Figures 2 and 3 in a third assembly position,

Figure 5

a section of the rotor blade from the Figures 2 to 4 in a fourth assembly position,

Figure 6

a rear case for a rotor blade according to a second embodiment of the invention in a first assembly position,

Figure 7

the back box Figure 6 in a second assembly position,

Figure 8

the rear box in the assembly position according to Figure 7 in a different direction,

Figure 9

a foot element for a rear box according to the second embodiment of the present invention,

Figure 10

2 shows a detailed view of a foot segment and a head segment of the rear case according to the invention in a decoupled state,

Figure 11

2 shows a detailed view of a foot segment and a head segment for a rear box according to the present invention in a coupled state,

Figure 12

a section of a rotor blade according to the present invention with a rear box according to a third embodiment of the invention,

Figure 13

a detailed view of the back box according Figure 12 , and

Figure 14

is a schematic representation of a part of the back box according to the Figures 12 and 13 .

Although certain features of preferred embodiments are only described with respect to individual exemplary embodiments, the invention also extends to the combination of individual features of the different exemplary embodiments with one another.

Figure 1 shows a wind turbine 100 with a tower 102 and a nacelle 104. A rotor 106 with three rotor blades 108 and a spinner 110 is arranged on the nacelle 104. During operation, the rotor 106 is set into a rotary movement by the wind and thereby drives a generator (not shown) in the nacelle 104.

The rotor blades 108 each have a rear box 112, by means of which they are designed as flexible rotor blades. The back box is divided into several segments, as can be seen from the following Figures 2 to 11 reveals.

A rotor blade with a rear box according to a first exemplary embodiment of the invention is shown in FIGS Figures 2 to 5 shown. That in the Figures 2 to 5 The rotor blade 108 shown has the rear box 112 in a region adjoining the rotor blade root 21. The rear box 112 has a suction-side surface 1, a pressure-side surface 3 and a rear edge 5 separating the pressure-side and the suction-side surface 1, 3. The connection side of the rear box 112 to the rotor blade 108 is arranged opposite the rear edge 5. A first edge 9a and a second edge 9b run on the connection side (see Figure 5 ), which delimits the surface 1, 3 of the rear box 112 and is adapted to the curvature of the rotor blade 108. In the assembled state, the rear edge 5 of the rear box 112 is aligned with the rear edge 7 of the rotor blade 108 and merges smoothly into it.

The rear box 112 has a foot segment 11 which has the connection side. The rear case 112 is subdivided and, according to the exemplary embodiment, has the Figures 2 to 5 a first head segment 13 and a second head segment 15. The first head segment 13 and the second head segment 15 each have a part of the rear edge 5. The head segment 13 is coupled to the foot segment 11 in a first subdivision plane 17, while the second head segment 15 is coupled in a second Subdivision level 19 is coupled to the foot segment 11. The first and second subdivision levels 17, 19 are slightly angled to one another.

How from the Figures 2 to 5 results, rails are formed in the region of the subdivision planes 17, 19 for the form-fitting coupling of the respective head segment to the foot segment. Arranged on the first subdivision level 17 are two rails 23, 25 which are guided in parallel and are set up in the head segment 13 for engagement with correspondingly designed rails (not shown). Arranged on the second subdivision level 19 are two rails 27, 29 which are guided in parallel and are set up to engage corresponding rails (not shown) in the head segment 15. As in Figure 5 reveals, the rails 27, 29 are arranged in the second subdivision level 19 at a closer distance from one another than the rails 23, 25 in the first subdivision level 17. As a result, the available space is exhausted to provide one for each of the head segments 13, 15 to ensure the highest possible stability. As in Figure 5 can also be seen, for fastening the rails 23, 25 and 27, 29 in the subdivision planes each have webs 31, 33 which at least partially and completely close the foot segment 11 in the exemplary embodiment shown.

The contemplation of Figures 2 to 5 also provides information about the assembly or disassembly of the head segments of the rear box 112 from the rotor blade 108. When changing from the state according to Figure 2 according to the state Figure 3 the head segment 13 closest to the rotor blade root 21 is first decoupled from the foot segment 11 by pushing the head segment 13 along the rails 23, 25 after unlocking (not shown). Then, as in Figure 4 is shown, the second head segment 15 is pushed along the second subdivision plane 19 and the rails 27, 29 from the foot segment 11. Figure 5 finally shows the foot segment 11 of the rear box 112 on the rotor blade 108 with the head segments 13, 15 disassembled (or not yet assembled). Subsequently, head segment 13 is pushed on and optionally secured.

The Figures 6 to 9 show a rear case 112 for a rotor blade 108 according to a second embodiment of the present invention. The rear box 112 according to the Figures 6 to 9 is configured essentially as the rear box 112 according to FIG the Figures 2 to 5 . The main differences are discussed below. The foot segment 11 of the rear box 112 according to the Figures 6 to 9 has a single, continuous subdivision level 37. A total of three head segments 13, 15, 35 are assigned to this subdivision level. The head segments 13, 15, 35 each have a part of the rear edge 5 of the rear box 112. The subdivision plane 37 extends, as before, in the embodiment of FIG Figures 2 to 5 applies to the subdivision levels 17, 19 there, from the suction side 1 to the pressure side 3. The rear box 112 according to Figures 6 to 9 is shown without end cover, which allows a view of the inside of the rear box. The foot segment 11 has a substantially continuous web 31, on which a plurality of rails, each of which is guided in pairs in parallel, is arranged (see Figure 9 ). The head segments 13, 15, 35 each have a web, shown in relation to the first head segment web 39, on each of which a pair of rails 41, 43 is arranged on the side facing the foot segment 11. The rails 23, 25 are in the position according to the respectively corresponding rails 41, 43 for the first head segment 13 Figure 6 coupled and are positively engaged. See also the Figures 10 and 11 . With regard to the edge courses 9a, 9b on the connection side of the rear box 112, reference is made to the explanations given above for the first exemplary embodiment.

In the Figures 7 and 9 The rear case 112 according to the invention is depicted in each case on a frame 201 in accordance with the second exemplary embodiment. In Figure 8 is the scaffold 201 as in Figure 6 omitted, which serves illustrative purposes.

In Figure 7 is shown how the head segments 13, 15 and 35 are each brought out of engagement with the rails respectively assigned to them on the foot segment 11 (see also Figure 9 ). The rails 41, 43 are indicated by way of example with respect to the first head segment.

A similar assembly or disassembly position is also in Figure 8 shown, where, however, a better view of the underside of the web 39 of the head segment 13 is made possible and the rails 41, 43 can be seen better.

How from the Figures 6 and 7 reveals, the head segment 13 has a step 45 on the pressure and suction side of the surfaces of the rear box 112. The foot segment 11 has a correspondingly designed step at the same point (based on the mounted state of the head segment 13 on the foot segment 11) on. The outer surface of the head segment 13 overlaps the underlying surface of the foot segment 11 up to the area of the step 45 in order to ensure a sealing of the surface transition between the head segment 13 and the foot segment 11. The step 45 is provided at a point at which the width of the head segment 13 and correspondingly the width of the web 31 is maximum. In the area between the step 45 and the hub-side end of the head segment 13, the surface of the head segment 13 overlaps the surface of the foot segment 11 in the assembled state, while in the area between the step 45 and the adjacent head segment 15 the surface of the foot segment 11 overlaps the surface of the Head segment 13 overlaps. This prevents damage to the lower edge of the head segment when mounting or dismounting the head segment 13.

In Figure 9 it can be seen that the web 31 in the subdivision plane 37 is composed of several segments. In each case spanning at least one of these segments, a total of six rails are arranged in pairs on the foot segment 11 of the rear box 112. The rails 23, 25 are assigned to corresponding rails of the first head segment 13 (see Figures 6 to 8 ). The rails 27, 29, which are arranged at a smaller distance from one another than the rails 23, 25, are assigned to corresponding rails of the second head segment 15. The rails 47, 49, which are arranged closer together than the rails 27, 29, are assigned to corresponding rails of the head segment 35. The distances are preferably selected such that the head segment 35 can be coupled to the foot segment 11 without coming into contact with the rails 27, 29 and 23, 25, and preferably further so that the head segment 15 is coupled to the foot segment 11 can without coming into contact with the rails 23, 25.

The Figures 10 and 11 show the arrangement of the rails on the foot segment and a corresponding head segment according to a preferred embodiment. According to this embodiment, the rails are all identical. A form-fitting engagement, which enables the lateral forces to be absorbed in all directions, is achieved only by mirror-inverted arrangement of the rails. A cross section through a rear box 112 according to the second exemplary embodiment is shown in detail. Nevertheless, the arrangement of the corresponding and identically designed rails is also to be adopted analogously for the first exemplary embodiment. The rails 23, 25 are arranged on the web 31 of the foot segment 11 (not shown). The rails have one each section 51 extending at right angles from the web and a section 53 oriented substantially parallel to the web 31. As a result, an essentially L-shaped profile is formed. The sections 53 aligned parallel to the web 31 point towards one another. Two corresponding rails 41, 43 are arranged on the web 39 of the first head segment 13 (not shown). In contrast to the rails 23, 25 arranged on the web 31 of the foot segment, the sections 53 oriented parallel to the web 39 point away from one another. In Figure 10 the rails are shown disengaged.

Figure 11 illustrated with a simple outline sketch for one of the two in Figure 10 shown pairs of rails the engaged situation. The horizontal sections 53 of the rail 25 and the rail 43 engage behind one another, as a result of which the force component perpendicular to the two webs 31, 39 is absorbed in each case. The force component parallel to the webs 31, 39 is absorbed in one direction by rails 25 and 41 and in the other direction by rails 23 and 43.

Alternative shapes to the L-shaped profile of the rails are, for example, in a C-shaped profile. As an alternative to the use of identical rails shown, the formation of a dovetail or trapezoidal profile with a male part and a female counterpart is still preferred. The latter also enables the use of a monorail system, that is to say only one rail per head segment or even a continuous rail on the foot segment and in each case with this corresponding rail on the one or more head segments.

In Figure 12 A rotor blade 108 is shown with a rear box 112 according to a third exemplary embodiment. The rotor blade 108 and the rear case 112 have structural similarities to the first and second exemplary embodiments of the present invention. With regard to the same reference numerals, reference is made to the above statements. The rear case 112 of the rotor blade 108 Figure 12 has a single foot segment 11, which is coupled along a continuous subdivision plane 37 to several, in this case three, head segments 13, 15, 35. The head segments 13, 15, 35 are arranged adjacent to one another and abut one another on subdivision planes 16, 18. In this way, the continuous rear edge 5 is formed between the suction side and pressure side 1.3 of the rear box 112.

The type of positive coupling of the head segments with the foot segment according to Figure 12 is in Figure 13 clarifies. As can be seen from the in Figure 13 In the overview shown at the bottom right, a hinge-like coupling is provided on the inside of the rear box 112. The foot segment 11 has a plurality of projections 303, each of which has a first recess. The head segment 13 or the head segments 13, 15, 35 have a plurality of second projections 301, each of which has a second recess. The first projections 303 of the foot segment 11 are spaced apart from one another at a distance 309. The distances 309 are each adapted to the width of the second projections 301 of the head segment or segments 13, 15, 35. It can be concluded from this that the distances do not all have to be the same, but can each differ from one another, as long as they are dimensioned in accordance with the opposite, corresponding projections 301. The second projections 301 of the head segment (s) 13, 15, 35 are spaced apart from one another at a distance 307, for which the same applies as for the distance 309 with respect to the projections 303 of the foot segment 11.

In order to achieve a form-fitting coupling between the foot segment 11 and the head segment (s) 13, 15, 35, the projections 301, 303 are aligned with one another. As soon as the alignment has taken place, an elongated body 305, which in principle forms the rod of a hinge, is introduced into the first and second versions until it extends through preferably all of the first and second recesses. In the exemplary embodiment in which the recesses are not strictly coaxial, but instead follow a curved path that corresponds, for example, to the contour of the rotor blade, the insertion of the elongated body 305 into the first and second recesses is ensured by sufficient elasticity of the elongated body.

The projections 301, 303, which are designed as tabs, are preferably fastened to the inside of the edges of the foot segment 11 or the head segments 13, 15, 35, in particular by means of gluing.

The arrangement and precise design of the projections is in Figure 14 shown schematically. Figure 14 shows a schematic plan view, as from the top right in Figure 14 is clear overview of the coupling state between two adjacent protrusions 301, 303. The first and second protrusions 303, 301 are formed by an outer layer 311, which consists of fiber-reinforced material, in particular glass fiber reinforced plastic. The amount of used Layers depend on the expected load on the tabs or projections. A wedge 317 made of a foam is arranged in the interior of the laid layers 311. At each end of the projections 301, 303, a coupling area is provided, in which an arcuate loop of the scrim is formed.

Within this loop is according to Figure 14 each arranged a high cylindrical wall made of plastic. The elongated body 305 is preferably accommodated within this wall without play. In order to improve the absorption of the compressive forces on the projections, the shock-absorbing high cylindrical wall 313 is enclosed by a layer 315 made of fiber-reinforced material, preferably glass-fiber-reinforced plastic.

A particular advantage of the form-fitting coupling according to the Figures 12 to 14 is seen in the fact that the coupling means, which are formed by the projections 301, 303, can be arranged directly on the inner wall on the suction side or pressure side 1, 3 of the rear case 112 or of the rotor blade 108, without separate webs for coupling in the Inside the rear box 112 must be drawn. The possibility of providing additional cross struts and webs for additional stiffening remains unaffected. The coupling means are protected against wind attack on the inside of the rear box and do not influence the flow profile. In addition, they enable simple and quick assembly with precise positioning of the parts relative to one another.

Claims (14)

1. A wind power installation rear box section (112) for mounting to a region adjoining to a rotor blade root (21) of a wind power installation rotor blade (108), comprising
   a pressure-side surface (3), a suction-side surface (1), a trailing edge (5) separating the pressure-side and suction-side surfaces, and a connecting side which is opposite to the trailing edge (5) and which is adapted for mounting to a corresponding connecting surface of the rotor blade (108),
   wherein the wind power installation rear box section (112) is sub-divided into a foot segment (11) having the connecting side and one or more head segments (13, 15, 35) which have the trailing edge (5) and which can be coupled in positively locking relationship to the foot segment (11),
   characterised in that the foot segment for the positively locking coupling has a plurality of mutually spaced projections (303) with a first recess and the head segment or segments respectively have a plurality of mutually spaced projections (301) with a second recess, wherein the projections of the foot segment can be oriented with the projections of the head segment or segments in mutually aligned relationship, and there is provided an elongate body (305) whose cross-section is adapted to the cross-section of the first and second recesses and which can be introduced into the plurality of first and second recesses when they are oriented in substantially mutually aligned relationship,
   or two rails (23, 25) arranged in parallel are associated with the foot segment (11) for each head segment (13, 15, 35) and each head segment (13, 15, 35) has two corresponding rails (41, 43) arranged in parallel for interengagement with the rails of the foot segment (11).
2. A wind power installation rear box section (112) according to claim 1
   characterised in that the foot segment (11) has for each head segment (13, 15) a separate sub-division plane (17,19) in which the head segment or segments (13, 15, 35) can be coupled to the foot segment (11), or the foot segment (11) has for a plurality of or all head segments (13, 15, 35) a continuous sub-division plane (37) in which the respective head segments (13, 15, 35) can be coupled to the foot segment (11).
3. A wind power installation rear box section (112) according to one of the preceding claims
   characterised in that the one or more sub-division planes (17, 19, 37) are so arranged that the maximum profile width of the rotor blade (108) is in a region of 4 m or less when the foot segment (11) is connected to the rotor blade (108).
4. A wind power installation rear box section according to claim 1
   characterised in that the projections of the foot segment and of the head segment or segments are arranged along a curved path, wherein preferably the curvature of the path corresponds to the contour configuration of the rotor blade.
5. A wind power installation rear box section according one of claims to 4
   characterised in that the projections are in the form of straps and preferably have a fabric comprising two or more fibre composite material layers, wherein preferably the projections each have a foam body enclosed by the fabric.
6. A wind power installation rear box section (112) according to claim 2
   characterised in that the rails can be brought into engagement with each other, preferably by being pushed on.
7. A wind power installation rear box section (112) according to claim 15
   characterised in that the rails (23, 25, 27, 29, 47, 49) on the foot segment (11) or the corresponding rails (41, 43) of the associated head segment (13, 15, 35) have a dovetail profile, or the rails (23, 25, 27, 29, 47, 49) of the foot segment (11) and the corresponding rails (41, 43) of the head segment or segments (13, 15, 35) are identical and are preferably of a substantially L-shaped cross-section.
8. A wind power installation rear box section (112) according to one of the preceding claims
   characterised in that at least two, preferably three or four, head segments are associated with the foot segment (11).
9. A wind power installation rear box section (112) according to one of the preceding claims
   characterised in that at the connecting side the pressure-side surface (3) and the suction-side surface (1) are respectively delimited by an edge (9a, 9b) whose respective edge configuration is adapted to the contour of the connecting surface of a rotor blade (108).
10. A wind power installation rear box section (112) according to one of the preceding claims
    characterised in that one or more regions for the application of bonding agents, preferably adhesive, are prepared in the interior of the rear box section (112).
11. A wind power installation rear box section (112) according to one of the preceding claims
    characterised in that the foot segment (11) and/or the head segment or segments (13, 15, 35) have in the region of the sub-division a respective leg (31, 33, 39) extending from the pressure-side surface (3) to the suction-side surface (1), wherein the rail or rails are respectively arranged on the legs.
12. A wind power installation rear box section (112) according to one of the preceding claims
    characterised by arresting means which are provided for selectively locking or releasing the relative position between the foot segment (11) and the at least head segment in the coupled condition, preferably in the form of a bolt connection.
13. A wind power installation rotor blade (108) comprising a supporting portion, a rotor blade root (21) embraced by the supporting portion for mounting to a rotor (106) of the wind power installation (100), a pressure-side blade surface, a suction-side blade surface and a trailing edge (7) separating the pressure-side and the suction-side surfaces,
    characterised in that mounted to a connecting surface in the region of the rotor blade root (21) of the rotor blade (108) is a foot segment (11) with the connecting side of a rear box section (112) according to one of claims 1 to 12, wherein preferably the foot segment (11) is coupled to one or more head segments (13, 15, 35) in such a way that a rear box section according to one of claims 1 to 12 is provided on the rotor blade (108).
14. A wind power installation (100) comprising a pylon (102), a pod (104) and a rotor (106),
    characterised by at least one wind power installation rotor blade (108) according to claim 13 connected to the rotor (106).

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